It has been more than twenty years since the development of personal computer. In the past twenty years, the personal computer has been largely improved in terms of its hardware configuration and software application function. Generally speaking, computer executable programs can be divided into two phases, one of which includes the program that is to be executed immediately after the power-on of the computer, i.e., the basic input output system (BIOS), and the other one includes all the application programs that are to be run under the environment of an operating system (OS) after the operating system has been booted.
The BIOS generally provides two functions, one of which is to conduct Power On Self Test (POST) and initialization, and the other one is program service process and hardware interrupt process.
The operating system and all the application programs are installed on the hard disk drive (HDD). When the BIOS has completed the POST and initialization, the operating system on the HDD is immediately booted into a dynamic random access memory (DRAM) of the system hardware to execute related programs.
However, the currently available personal computer has at least the following disadvantages:                (1) Lacking timeliness: In recent years, while the personal computer with built-in digital still camera (DSC, also referred to as CMOS camera module) and digital television (DTV) functions has become highly popularized, these two functions must be operated under the environment of an operating system, such as Windows series operating systems, Linux, or the like, and so are other programs, such as address book software and To-Do list software. And, it takes more than one to two minutes from powering on the computer to successfully booting the operating system and then running a certain application program. Thus, the existing personal computer lacks timeliness.        (2) Insufficient stability: In the past twenty or more years, the operating system for a personal computer is placed on the HDD. All computing can be conducted only when the operating system has been booted into the DRAM of the computer. A spindle motor of the HDD in working rotates at a high speed. Generally, a 2.5″ HDD has a rotating speed from 5400 to 7200 rpm, while a 3.5″ HDD has a rotating speed higher than 10,000 rpm. Data is accessed via a voice coil motor and a stepping motor, which reciprocate on the hard disk, and the HDD reads and writes such reciprocating movements to complete the data access. Under the working conditions of high rotating speed and high working temperature, the HDD is easily damaged due to an external vibration force, resulting in damage or loss of important data stored thereon. For example, the HDD of the notebook computer has an annual return rate (ARR) or annual failure rate (AFR) generally between 0.75% and 1%. In other words, there are about 1% of notebook computers being failed and requiring repair each year. That is why most personal computer users have to buy an external HDD as a backup data storage device.        (3) Potential risk in computer security: Due to the quick development of Internet in recent years, any computer owned by any user and used at any time and place is subject to virus invasion. The virus threats just exist around you! There are various kinds of anti-virus programs constantly developed against different computer viruses and being available in the market. However, these anti-virus programs fail to catch up with the development of computer viruses and could not solve the problem of virus invasion successfully. Even if the computer users have tried every way to protect their computers against virus invasion, there are still a lot of users who have to re-install the operating system of the computer due to virus invasion.        
It is therefore tried by the inventor to develop a computer system with two operating devices and a control method thereof in an attempt of overcoming the above-mentioned disadvantages.